1. Field of the Invention
The present invention relates to an image forming apparatus, and particularly to an image forming apparatus connectable to an external centralized control unit or the like through a communication line.
2. Description of the Related Art
Generally, in image forming apparatuses which form hard copy images using electrophotography process such as a copying machine, a facsimile, and an optical printer, display means for informing operators that some kind of trouble has occurred making image forming impossible is provided. Accordingly, small troubles such as lack of consumable goods such as paper and toner, or paper jams can be solved by operators themselves by supplying the consumable goods or removing the jammed paper to start image forming again.
As for troubles which operators can not handle, a display of a so-called service man call for demanding a contact with a service man appears.
Conventionally, some of there image forming apparatuses are configured to be connectable to an external control unit (host) through a communication line.
For example, the copying machine disclosed in Japanese Patent Laying-Open No. 59-142559 is configured to output data showing the conditions of use such as the number of times of copying according to a control signal from the host.
According to the copying machine, even if the copying machines are provided at places mutually spaced apart, the plurality of copying machines can be concentrically controlled by a host provided at a single place, so that totalization of use conditions or the like of the respective copying machines can be easily carried out.
In addition, in the copying machines shown in the above-mentioned Official Gazette, interphone devices which become communicatable upon a call from the host side are provided.
Recently, a centralized control system having objects of rapid maintenance and low maintenance cost for respective image forming apparatus has been developed, in which each of a plurality of image forming apparatuses provided on each user side and a control unit (host) at a maintenance station (service station) where service men are waiting are connected through a communication line.
The maintenance includes, in addition to repair of faults, confirmation of operating conditions, adjustment of each portion according to the conditions, and so forth.
In a conventional image forming apparatus, however, although it is connectable to a communication line, the operator side can not call a service station employing the communication line. Therefore, the operator had to try to have a contact with a service man by means of another communication means, such as a telephone, every time he demands a visit of the service man (a service visit).
A service visit is usually requested when an operator makes a determination according to his subjective point of view that the image quality is degraded even if image forming is possible, that is, when a user claim is produced, in addition to the above-described case where an image can not be formed.
On the other hand, a service man tries to know the contents of the trouble or conditions on the basis of the information given by the operator when he receives a request for a service visit. However, although he can know the outline of the conditions, he can not properly understand a cause of the trouble, the extent of the image quality, the details of the conditions and so forth.
Accordingly, in the service station, it has been difficult to select when a service visit should be made according to the extent of emergency, and repairing parts to be prepared for the service visit. Also, on the visited user side, the work should be started by conforming the condition, so that the efficiency of maintenance is low.